Mold on Seedling grow medium

luigiwu · March 29, 2014

I see white powdery stuff on top of the grow medium on my seedlings - mold?

I think I'm over watering them (though always from the bottom.) And have just put a fan on them - hopefully not too late. So now how do I remedy the situation? I was told spray the 3% hydrogen peroxide that you get from the drugstore. Will it harm the seedling leaves? How often and how much do I spray?

My poor babies - first time growing from seeds and steep learning curve!
Thanks!
This is a kale seedling but the soil around my tomatoes also have this powdery stuff.

JamesL · March 29, 2014

Luigiwu,
Posted about this a few days ago here.
http://tomatoville.com/showpost.php?...8&postcount=27

I would go with .75% first. You can always raise the dose if needed. Get a small plastic spray bottle. Heavy spray the top of the mix and light spray the plants. Hopefully you will only have to spray once.
I have gone as high as 6% on full grown plants outside, but I haven't sprayed seedlings with higher than 1%.
You may or may not end up with brown spots on the leaves depending on what if any damage is being caused by the mold/mildew and then the h2o2 killing it.
If you are at all nervous about spraying the plants themselves, spot spray on 1 or 2 plants only at first. The h2o2 will oxidate and break down in a matter of hours and you would know the next day as to effectiveness.
Let us know what you decide to do!

luigiwu · March 30, 2014

Hi James, I got the drugstore 3% and use it straight up in spray bottle before I saw your posting here. Approx 3 squirts on the top of the soil, all the while holding, shielding the plant because I wasn't sure it was safe for them yesterday. This morning's report is things look more or less the same unfortunately.

Do I dillute and spray more or?? How do I know if its working or not? Will the white stuff go away if its working?

Hey, I was at Hick's yesterday and they have ProMix BX that's 2.8cu (I think) for $26ish... Is that the right ProMix? they had a lot of other ProMix products like one packaged for Veggies... I was so overwelmed and left with Hamptons Estate Professional Potting Mix instead... lol - I hope its good. The last bag of Miracle Gro I bought was just terrible...

I also ended up repotting some of my tomato seedlings. After scraping off as much of the white stuff, I put more dry potting mix on top and didn't water or spritz them... was that a bad idea? Also after the peroxide application, would you leave it off the growlights?

amideutch · March 30, 2014

I've found that Actinovate and Colloidal silver will take care of most mold, bacteria and fungi on seedlings. By the time I get ready to pot up my seedlings the CS has been leached out of the expanded peat pellets I use and will not affect the myco's and other bacteria I use in my dip solution prior to plant out.

Ami

ginger2778 · March 30, 2014

For reference, I get a 3.8 cu ft bale of Promix BX for $28.
Marsha

Quote:

Originally Posted by luigiwu

Hi James, I got the drugstore 3% and use it straight up in spray bottle before I saw your posting here. Approx 3 squirts on the top of the soil, all the while holding, shielding the plant because I wasn't sure it was safe for them yesterday. This morning's report is things look more or less the same unfortunately.

Do I dillute and spray more or?? How do I know if its working or not? Will the white stuff go away if its working?

Hey, I was at Hick's yesterday and they have ProMix BX that's 2.8cu (I think) for $26ish... Is that the right ProMix? they had a lot of other ProMix products like one packaged for Veggies... I was so overwelmed and left with Hamptons Estate Professional Potting Mix instead... lol - I hope its good. The last bag of Miracle Gro I bought was just terrible...

I also ended up repotting some of my tomato seedlings. After scraping off as much of the white stuff, I put more dry potting mix on top and didn't water or spritz them... was that a bad idea? Also after the peroxide application, would you leave it off the growlights?

JamesL · March 30, 2014

Luigiwu,
3% on the soil surface is not going to hurt you at all. I haven't sprayed seedlings with that strength so I can't say what it will do on the foliage.
Actinovate that Ami mentions is a great product as well.
Promix makes a lot of different versions, BX is one of the most popular.
Hamptons Estate - I am not a fan. Would use it in the yard instead.....
The 3.8 bales of BX can be had at the Queens hydro store for around $35.
I have never seen them at Hicks.

nnjjohn · March 30, 2014

I'm wondering if spray bottling too much water/liquid fertilizer ( even if it is diluted) contributes or causes molds or leave problems on seedlings? The seedling mix MG in my case) bag says it is fortified with all the minerals /grow fertilizers for the seedlings needs until the seedling are to be transplanted in bigger containers or in the garden, I am not so sure of anything..just asking..

luigiwu · March 31, 2014

Quote:

Originally Posted by amideutch

I've found that Actinovate and Colloidal silver will take care of most mold, bacteria and fungi on seedlings. By the time I get ready to pot up my seedlings the CS has been leached out of the expanded peat pellets I use and will not affect the myco's and other bacteria I use in my dip solution prior to plant out.

Ami

Have you used Serenade on seedlings before? I have that...

SharonRossy · March 31, 2014

I found white fuzzy stuff on my seedling mixture also. It was recommended to add a light amount of seedling mixture on top to absorb some of the moisture. This is the first time it happened and I freaked, but the seedlings look fine. I'm not spraying until some of the moisture is absorbed. BTW ii used MG seed starting mixture.

luigiwu · March 31, 2014

Hi Sharon, so you think its okay just to add something dry on top? without treating the mold beforehand? I have some of the Ultrasorb that people are using to grow/start seedlings in and was thinking of putting that on top.
What you see in these pictures are potted up seedlings. I orginally started them all (densely planted) in miracle gro seedling mixture. When the first true leaves started, I seperated each plant and just put them in regular miracle gro potting mix.

amideutch · April 1, 2014

Serenade is Bacillus subtilis which is organic. Give it a try on a couple seedlings and see how it works.

Ami

Cole_Robbie · April 1, 2014

The pro-mix I use grows what looks like to me to be the same white mold, and I just ignore it. I don't think it hurts anything. Natural/Organic fertilizers tend to grow mold. I still use Terracycle fertilizer, which will grow some very impressive fuzzy white mold if left in the top of the mix, because plants still seem to love it.

Damping off is what kills almost all the plants I lose, and I have seen no correlation to mold. Algae, yes, but that is from the container mix getting mucky. I'm doing a lot better by mixing more perlite into my seed-starting mix. I had been using a mix of almost all vermiculite, which is great for sprouting the seeds, but then before they can grow big enough to transplant, the vermiculite will hold too much water around the base of the stem. With just a little nutrient in the top layer, pythium bacteria overwhelm it, and the stem rots in half where it touches the mix. Adding perlite aerates that layer, helping the aerobic good bacteria overcome the anaerobic pythium bad guy bacteria.

SharonRossy · April 1, 2014

I scraped off the fuzzy stuff luckily it was on only a few and I took out the wooden name tags and wiped them with a Clorox cleaning cloth. In my moment of panic I decided to try an loosen the soil in one container only to realize I killed a seedling so for now I'm just leaving well enough alone. Yes I think it's ok to add dry mix on top.
I have not added any fertilizer and won't until I see true leaves which are just emerging.

bower · April 2, 2014

I don't like the white mold on the soil surface, although I have only suspicions not proof of any harm. I've seen it in the cell with seeds that didn't germinate, so I suspect it may affect seeds if not larger plants.
I have found that watering or heavily misting right on the mold will suppress it, but it will often return after the soil dries out. So I tried using a teaspoon of gentian leaf tincture in 1 liter of water in my spray bottle, and the mold doesn't return after spraying it once. It's a home made product from gentiana lutea which has some antifungal properties, easily made by extracting some fresh leaves in ordinary vodka.

luigiwu · April 2, 2014

Quote:

Originally Posted by bower

I don't like the white mold on the soil surface, although I have only suspicions not proof of any harm.

I feel exactly the same way... though this is my first year starting from seed. I went to pot up some seedling right now. When I opened the bucket of miracle gro (I know, I know) there was the same white trace of stuff all over it. I don't know what to do now... should I use it or not?

The miraclegro comes from a bigger bag I just bought. I put some in a bucket to have on hand, you know during late night planting-cravings.

but now I don't know what to do...

March 29, 2014	#1
luigiwu Tomatovillian™ Join Date: Jun 2013 Location: ny Posts: 1,219	Mold on Seedling grow medium I see white powdery stuff on top of the grow medium on my seedlings - mold? I think I'm over watering them (though always from the bottom.) And have just put a fan on them - hopefully not too late. So now how do I remedy the situation? I was told spray the 3% hydrogen peroxide that you get from the drugstore. Will it harm the seedling leaves? How often and how much do I spray? My poor babies - first time growing from seeds and steep learning curve! Thanks! This is a kale seedling but the soil around my tomatoes also have this powdery stuff. Last edited by luigiwu; March 29, 2014 at 07:39 PM.

March 30, 2014	#3
luigiwu Tomatovillian™ Join Date: Jun 2013 Location: ny Posts: 1,219	Hi James, I got the drugstore 3% and use it straight up in spray bottle before I saw your posting here. Approx 3 squirts on the top of the soil, all the while holding, shielding the plant because I wasn't sure it was safe for them yesterday. This morning's report is things look more or less the same unfortunately. Do I dillute and spray more or?? How do I know if its working or not? Will the white stuff go away if its working? Hey, I was at Hick's yesterday and they have ProMix BX that's 2.8cu (I think) for $26ish... Is that the right ProMix? they had a lot of other ProMix products like one packaged for Veggies... I was so overwelmed and left with Hamptons Estate Professional Potting Mix instead... lol - I hope its good. The last bag of Miracle Gro I bought was just terrible... I also ended up repotting some of my tomato seedlings. After scraping off as much of the white stuff, I put more dry potting mix on top and didn't water or spritz them... was that a bad idea? Also after the peroxide application, would you leave it off the growlights? Last edited by luigiwu; March 30, 2014 at 12:04 PM.

March 30, 2014	#4
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	I've found that Actinovate and Colloidal silver will take care of most mold, bacteria and fungi on seedlings. By the time I get ready to pot up my seedlings the CS has been leached out of the expanded peat pellets I use and will not affect the myco's and other bacteria I use in my dip solution prior to plant out. Ami __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

March 30, 2014	#7
nnjjohn Tomatovillian™ Join Date: Mar 2013 Location: northern new jersey Posts: 683	I'm wondering if spray bottling too much water/liquid fertilizer ( even if it is diluted) contributes or causes molds or leave problems on seedlings? The seedling mix MG in my case) bag says it is fortified with all the minerals /grow fertilizers for the seedlings needs until the seedling are to be transplanted in bigger containers or in the garden, I am not so sure of anything..just asking.. __________________ john

April 1, 2014	#11
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	Serenade is Bacillus subtilis which is organic. Give it a try on a couple seedlings and see how it works. Ami __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

March 29, 2014	#2
JamesL Tomatovillian™ Join Date: Nov 2011 Location: Long Island NY Posts: 1,992	Luigiwu, Posted about this a few days ago here. http://tomatoville.com/showpost.php?...8&postcount=27 I would go with .75% first. You can always raise the dose if needed. Get a small plastic spray bottle. Heavy spray the top of the mix and light spray the plants. Hopefully you will only have to spray once. I have gone as high as 6% on full grown plants outside, but I haven't sprayed seedlings with higher than 1%. You may or may not end up with brown spots on the leaves depending on what if any damage is being caused by the mold/mildew and then the h2o2 killing it. If you are at all nervous about spraying the plants themselves, spot spray on 1 or 2 plants only at first. The h2o2 will oxidate and break down in a matter of hours and you would know the next day as to effectiveness. Let us know what you decide to do!

March 31, 2014	#9
SharonRossy Tomatovillian™ Join Date: Jul 2012 Location: Montreal Posts: 1,140	I found white fuzzy stuff on my seedling mixture also. It was recommended to add a light amount of seedling mixture on top to absorb some of the moisture. This is the first time it happened and I freaked, but the seedlings look fine. I'm not spraying until some of the moisture is absorbed. BTW ii used MG seed starting mixture.

April 1, 2014	#12
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	The pro-mix I use grows what looks like to me to be the same white mold, and I just ignore it. I don't think it hurts anything. Natural/Organic fertilizers tend to grow mold. I still use Terracycle fertilizer, which will grow some very impressive fuzzy white mold if left in the top of the mix, because plants still seem to love it. Damping off is what kills almost all the plants I lose, and I have seen no correlation to mold. Algae, yes, but that is from the container mix getting mucky. I'm doing a lot better by mixing more perlite into my seed-starting mix. I had been using a mix of almost all vermiculite, which is great for sprouting the seeds, but then before they can grow big enough to transplant, the vermiculite will hold too much water around the base of the stem. With just a little nutrient in the top layer, pythium bacteria overwhelm it, and the stem rots in half where it touches the mix. Adding perlite aerates that layer, helping the aerobic good bacteria overcome the anaerobic pythium bad guy bacteria.

April 2, 2014	#14
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,793	I don't like the white mold on the soil surface, although I have only suspicions not proof of any harm. I've seen it in the cell with seeds that didn't germinate, so I suspect it may affect seeds if not larger plants. I have found that watering or heavily misting right on the mold will suppress it, but it will often return after the soil dries out. So I tried using a teaspoon of gentian leaf tincture in 1 liter of water in my spray bottle, and the mold doesn't return after spraying it once. It's a home made product from gentiana lutea which has some antifungal properties, easily made by extracting some fresh leaves in ordinary vodka.